APM 2.6 - GPS issues

Hoping someone can point me in the right direction… no pun intended.

Done all the calibrations, have a good GPS lock, etc, etc, etc. When I go into loiter mode it wants to start to bank left and slowly fly off.  Sometimes it even does weird things with the throttle like drop the RPM’s drastically. 

What am I doing wrong?




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  • I think if the place will take it back it's going back. If they won't take it back it's gonna get set on a post at my shooting range.

    • or sell it on RCG's classifieds and recoup some of your money. Even with the power issue people will buy it if it is cheap enough and you let them know the issues you are having with it.

  • logs would help. The dataflash logs not the telemetry logs.

    also you really need to move your RX's antennas further away from your GPS.

    • As requested.

      1 12-31-1969 4-00-00 PM.bin

      1 12-31-1969 4-00-00 PM.bin.log

      • two pretty serious issues I see off the bat

        1: your VCC is extremely low. It should be around 4.9- 5.2v and yours is about 4.5v and dips below 4.4v this is not good.

        2: your GPS is having a hard time and this could well be that it is under volting and your X8R antennas being right next to it will no doubtfully cause issues.

        You've disabled some of the logging that would help as well such as vibrations, power module data, etc so I can't glean any info from that aspect.

        I'd be concerned about the low voltage on your APM though.

        • See anything better?

          1 12-31-1969 4-00-00 PM.bin.log

          1 12-31-1969 4-00-00 PM.bin

          • no much worse :(

            looks like brownouts, ekf errors, GPS glitching, log truncation, And still low VCC to the APM.

            • Damn, what I have a bad board? That's what I get for buying one off Ebay.

              • no it looks like an improperly setup board/rig. The EKF issues are normally a component placement/vibration/calibration issue.

                The low VCC issue has been seen many times powering via ESC's BEC 

                The GPS issue is probably it needs to be further away from EMF [ie further away from the APM/RX/Antennas]

                What isn't showing is a hardware fault with the APM itself.

                • Hell what do I need to do, sprinkle pixie dust and get it blessed by a Shaman? Shouldn't be that hard and there's not much room to move things around. I've seen APM's on a lot smaller quads than I'm running GPS and all. I pulled the red power lines on the ESC's, installed the power module moved some things around and put the antennas as far away as I can get them and it only got worse. WTF.

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